> Hi,
>
> I want to use view models as a wrapper around a persisted domain entity to
> simply present an alternative view of that entity. The idea of caching such
> a view model doesn't make sense to me, rather I want the persisted domain
> entity to be cached and the view model (representation of it) to be
> recreated each time that its needed, probably by having a constructor that
> includes the domain entity as a parameter.
>
> I can create a DomainObject with nature = Nature.INMEMORY_ENTITY, and make
> it non bookmarkable, how the title is still a link to a now cached entity
> that cannot be recreated.
>
> Stack trace:
>
>    - org.apache.wicket.WicketRuntimeException
>    - Can't instantiate page using constructor 'public
>
>  org.apache.isis.viewer.wicket.ui.pages.entity.EntityPage(org.apache.wicket.request.mapper.parameter.PageParameters)'
>    and argument
>
>  'objectOid=[*one.projectviewmodel:PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0iVVRGLTgiPz4KPG1lbWVudG8vPg==]'.
>    An exception has been thrown during construction!
>    -
> org.apache.wicket.session.DefaultPageFactory#newPage(DefaultPageFactory.java:194)
>
>
> I can see a way to do what I want by creating a persistent domain entity
> that references the persistent domain entity of interest, and then just has
> getters that refer to the equivalent getter of the domain entity of
> interest.
>
> This need has been created my desire to have a very simple view of a domain
> entity without using tabs in the layout.xml and the admin view that does
> use layout.xml, but I suspect its a more general need.
>
> Steve
>

> We do something similar to this in Estatio... take a look at
> IncomingDocAsInvoiceViewModel (or something like that).
>
> If you use Jaxb view models, then it simply requires a property referencing
> the underlying domain entity (which should be annotated with
> XmlAdapter(PersistentEntityAdapter.class) so that Jaxb can serialize the
> reference into an oid.
>
> HTH,
> Dan.
>
> On Wed, 4 Oct 2017, 04:45 Stephen Cameron, <[EMAIL PROTECTED]>
> wrote:
>
> > Hi,
> >
> > I want to use view models as a wrapper around a persisted domain entity
> to
> > simply present an alternative view of that entity. The idea of caching
> such
> > a view model doesn't make sense to me, rather I want the persisted domain
> > entity to be cached and the view model (representation of it) to be
> > recreated each time that its needed, probably by having a constructor
> that
> > includes the domain entity as a parameter.
> >
> > I can create a DomainObject with nature = Nature.INMEMORY_ENTITY, and
> make
> > it non bookmarkable, how the title is still a link to a now cached entity
> > that cannot be recreated.
> >
> > Stack trace:
> >
> >    - org.apache.wicket.WicketRuntimeException
> >    - Can't instantiate page using constructor 'public
> >
> >  org.apache.isis.viewer.wicket.ui.pages.entity.EntityPage(
> org.apache.wicket.request.mapper.parameter.PageParameters)'
> >    and argument
> >
> >  'objectOid=[*one.projectviewmodel:PD94bWwgdmVyc2lvbj0iMS4wIiBlbm
> NvZGluZz0iVVRGLTgiPz4KPG1lbWVudG8vPg==]'.
> >    An exception has been thrown during construction!
> >    -
> > org.apache.wicket.session.DefaultPageFactory#newPage(
> DefaultPageFactory.java:194)
> >
> >
> > I can see a way to do what I want by creating a persistent domain entity
> > that references the persistent domain entity of interest, and then just
> has
> > getters that refer to the equivalent getter of the domain entity of
> > interest.
> >
> > This need has been created my desire to have a very simple view of a
> domain
> > entity without using tabs in the layout.xml and the admin view that does
> > use layout.xml, but I suspect its a more general need.
> >
> > Steve
> >
>